1. Field of the Invention
The present invention relates to an image processing apparatus and an image processing method which extract a predetermined area (a photographic print or the like) from a photographed image.
2. Description of the Related Art
In recent years, digital cameras have been popularized as a photographing device, and digitization of photographs has been in progress.
Digitization of photographs has a variety of advantages. For example, photographs can be compactly stored, it is easy to copy photographs, and photographs can be browsed in a variety of ways such as in succession or in random order. From the standpoint of such advantages, digitization of conventional photographs obtained by using silver salt films will be widely used. Because digital cameras have been popularized recently, many people have such conventional photographs. The conventional photographs include photographs on printing papers and developed films. Hereinafter, those are generally referred to as “photographic prints”.
Photographic prints can be digitized by, for example, causing a flatbed scanner to scan the photographic prints. As is commonly known, the original colors of photographic prints discolor (fade) due to chemical change as time passes. For this reason, some scanners have an image processing device, which performs color fading correction for correcting discoloration, mounted thereon.
An example of a conventional image processing device which performs color fading correction is described in Jpn. Pat. Appln. KOKAI Publication No. 2002-101313. The conventional image processing device described this Patent Document detects a level of color fading of an acquired image, and performs color fading correction according to the result of the detection. The level detection makes it possible to appropriately perform color fading correction by merely acquiring an image.
It is necessary to apply the level detection only to images to be objects of color fading correction. Otherwise, it is impossible to precisely identify how color fading occurred on the images. As is commonly known, a flatbed scanner is caused to scan a scanning object which is directly placed on a scanning table, or is set on a feeder. Therefore, it is possible to easily scan only a photographic print to which color fading correction is to be applied.
By the way, photographic prints are generally attached to an album or the like (here, including a method for putting photographic prints into a file at least one side of which is transparent). Photographic prints affixed to the album cannot be set on a feeder. Moreover it is difficult to set them appropriately on a scanning table. It is ordinary impossible to scan only a target photographic print affixed to an album. For this reason, photographic prints affixed to an album are generally removed from the album when it is scanned. Consequently, when a scanner is caused to scan photographic prints, it is necessary to carry out the following burdensome works for each photographic print. That is, a photographic print is removed from the album, and is placed on a scanning table, and after scanning is completed, the photographic print on the scanning table is affixed to the album again.
Photographic prints may be damaged at the time of being removed from the album. For example, when the photographic prints are stuck to a clear sheet covering photographic prints in the album, there is a high possibility of damaging them. Therefore, it is desirable to scan the photographic prints without removing them from the album.
It is possible to scan photographic prints without removing them from album using the invention described in Jpn. Pat. Appln. KOKAI Publication No. 2002-354331. However, it is more convenient and preferable for a user to be able to use a portable photographing device such as a digital camera. With a portable photographing device, it is possible to photograph an object in an arbitrary positional relationship. The advantage that the object can be photographed in an arbitrary positional relationship means, on the other hand, that it is difficult to know under what photographic condition (a positional relationship with a photographing device and an object, a positional relationship with the object and another object, and the like) a photographic print has been actually photographed. This makes it difficult to recognize a specific photographic print.
Moreover, an album generally stores many photographic prints. It has been difficult to precisely recognize a target of color fading correction from among these many photographs.